, a cross between an organism showing a dominant phenotype (heterozygous, e.g., Ww) and the recessive parent (homozygous white, ww) is called a test cross . The textbook provides a specific example using violet and white flowers, showing that such a cross yields progenies in a 1:1 ratio of dominant (violet) to recessive (white) phenotypes . Therefore, out of 40 progenies, half (20) will be violet and half (20) will be white.